The more simple in vitro models rely on non-cardiac cell lines that express a recombinant human ether-á-go-go related gene (hERG) potassium channel, as this channel plays a major role in cardiac repolarization and hERG-blocking compounds frequently cause ventricular arrhythmias [9, 10]. The gene discussed is KCNH2; the disease is Ventricular arrhythmia.